With the popularity of smart phones and high requirement of transmission rate, capacity exhaustion will be the most severe problem for mobile networks in the 4G and Beyond 4G (B4G) era. With the advent of mobile devices supporting multiple interfaces (e.g., 3GPP, WiFi, WiMAX, etc.), traffic offload from 3GPP to non-3GPP could relieve the capacity exhaustion problem. One way to realize traffic offload is via IP flow mobility (IFOM). IFOM allows selective movement of IP data flows between different access networks supporting different access technologies. IFOM solutions can be based on three different protocols: Dual-Stack Mobile IPv6 (DSMIPv6) protocol, Proxy Mobile IPv6 (PMIPv6) protocol, and GPRS Tunneling Protocol (GTP).
In 3GPP TR 23.861, multi-access packet data network (PDN) and IP flow mobility (IFOM) have been discussed. Various solutions for multi access PDN connectivity and IP flow mobility including IP flow mobility solutions for S2c (DSMIPv6) and IP flow mobility solutions for S2a (PMIPv6) are studied. The solutions include IP flow mobility based on routing filters UE provides to PDN-GW and IP flow mobility based on PCC (policy control and charging rules) for network-based mobility management procedures. However, IP flow mobility solutions for GTP have not been fully investigated.
US2009/0303932 A1 patent publication discloses a method and apparatus for facilitating network-based control of a forwarding policy used by a mobile node. The mobile node receives access network-specific signaling that is related to an IP flow. The mobile node then selects from multiple access networks to send the IP flow based on the signaling. The mobile node may also update a forwarding policy to indicate that the IP flow should be sent over the access network.
US2010/0080172 A1 patent publication discloses a proxy mobile internet protocol (PMIP) in a multi-interface communication environment. A communication entity (e.g., UE, AGW, PDN GW, etc.) notifies another communication entity to use a single IP address for connections to multiple AGWs. The communication entity also sends information that is related to at least one of the UE's IP flows to another communication entity.
US2011/0090794 A1 patent publication discloses techniques for wireless data communications employing IP flow mobility. Techniques for IP flow mobility are based on mobile IP protocols, such as PMIP and CMIP. The technique allows an access terminal (AT) moves at least one IP data flow, which is established between the AT and a first access network using a first technology type, to a second access network using a second technology type, while maintaining other data flows to the first access network. AT uses the same IP address to transmit or receive data flows through both of the access networks by maintaining a flow map in both mobility anchor and AT to identify the access gateway and thus the technology type each flow should be directed.
Many existing core network infrastructures, however, do not fully support mobile IP protocol. For example, the general packet radio service (GPRS) is a packet data mobile data service that supports mobile IP via GPRS tunneling protocol (GTP). It is thus desirable that IP flow mobility can also be supported based on GTP.